Revolving-ring-hearth oven



July 29, 1930. HONyGMANN ET AL 1,771,756

REvoLvING RING HEARTH ovEN Filed June 2, 1926 4 Sheets-Sheet l INVENTORS: "fwdfffl//m s iV l4 sheets-sheet 2 l NVE N T0 RS Z mapzz firk/n? ai L. HONIGMANN ET AL REVOLVING RING HEARIH OVEN Filed June 2. 1926 July 29, 1930.

July 29, 1930. l.. HONIGMANN Er AL V1,771,756

REVOLVING RING HEARTH OVEN Filed June 2. 192s 4 sheets-sheet 5 w Y uw A..

July 29, 1930- L. HONIGMANN ET AL l1,771,756

` REVOLVING RIG HEARTH OVEN Filed June 2. 1926 4 sheetsheet 4 ATTORNEYS Patented July 29, 1930 UNITED STATI-:s PATENT4 ol-r-lolz- LUDwre HONIGMANN, or mi) ToLz, AND FRIEDRICH nanrmne, or MUNICH, GERMANY nnvoLvING-ninq-Hm'rn ovEN l Application l'ed June 2, 1926, Serial No. 113,288, and in Germany June 3, 1925.

As is known, a revolvinring hearth oven conslsts of an annular mu e the lower opening of which is'closed by a revolving ring' forming the hearth onto which the oven ma- 5 terial is charged, mostl thin layer.v Some dicu ty is encountered in the sealing of the oven chamber against the outside which isnecessary in order, on the y one hand, to avoid losses of heat and, on the i other, to protect the 'supporting and driving means ofthe hearth against the. effect of the heat.v This problem which, in itself, is diflicult of solution is, however, increased if heating from below, which is highly desirable,

is to be resorted to.

The object of this invention is a simple,and inexpensive solution of this problem.

In its solution, it is to be borne in mind that the ring hearth, usually constituted by a single plate, has to fulfil a double function, i. e. on the one hand, heat insulation a ainst the outside and, on the other, the carrying of the charge and the heating thereof. While the rst function necessitates the construction of the plate from, or its coating with, heat-insulating material and keeping it cool, the second function makes it desirable to produce the plate from heat conductive material and to render it accessible to heat from all sides 3o possible.

From this consideration y emanates the fundamental idea fof the invention residing in the provision of two separate rings indi- .vidually performing the respective functions but rigidly connected so as to be driven in unison. -This results in the possibility of enabling both plates to be so journalled and made of such substances' as to adapt them each to perform its respective work in a comi 40 pletely satisfactory manner.

According to the invention, therefore, the revolving ring hearth oven, heated from below, comprises two superposed ring shaped members connected by appropriate supports so that the lower ring formingthe carrier ring, and closing the oven chamber, is provided with the supportingj and driving means, while the upper ring, eing the working hearth proper, is charged with the material to be treated and is situated above the in the form of a.

grooves become filled with llower ring at such a distance as to be heated --become deformed by the heat of the oven,

particularly if it is rigidly connected to the 05 supporting and travelling structure. The provision of expansion grooves does not attain the object aimed at, firstly, because these articles of the oven material whereby their effect is -de- 1o feated and, secondly, because the gas tightclosure of the oven would bev affected thereby.

A further characteristic of the invention resides in a hearth arrangement whereby the carrier ring'is connected to the hearth ring 75 proper by a connecting structure which permits of relative movement of the hearth ring. This connecting structure may consist of roller members arranged at intervals and transversely of the carrier ring and upon which the working hearth is freely supported. Moreover, the carrier ring is supported by the travelling frame by means of a pivotal connection. This arrangement provides a double link-like connection whereby the g5 hearth arrangement really comprises three constituents, in themselves rigid, i. e. the travelling structure; the carrier ring and the working ring or hearth proper having between them pivotal connections so as to 9o enable relative displacements or swinging movements between the hearth and the travelling structure should the hearth,-as a conseframe with thecarrier ring, and the latter large quantities cannot obviously be treated at once@V It is therefore of importance to enlarge the surface area of the hearth, if possible. The size of the individual ring plates is limited for practical reasons. Hitherto it was necessary, in order to obtain larger outputs, .to arrange several such ovens. This, however, met with the difiiculty that the revolvin hearth type of oven, owing to its circular s ape, occupied much space.

Accordingly, a further feature of the invention resides 1n an. oven arrangement 1n which` this defect is obviated. This is achieved by several ovens being built one within the other so that an oven of a certain diameter concentrically embraces one of smaller diameter. These concentrica-l oven chambers, 'arranged-in which are likewise concentricallyrevolvinghearths, are by preference arranged within a common brickwork casing. In this way considerable economy is obtainedinregard to space while the losses of heat by radiation are minimized.

A -further advantage resulting from this Aoven arrangement resides in the concentri-4 cally arranged oven units supplementing one another in so far as they enable the material to be conve ed from the discharge point of one oven directl to the charging point of the next oven. rThus the treatmentby heat, to thev extent to which it could not be completed in one oven,v is continued in the next oven chamber.' This possibility lcan be utilized' particularly in multi-phase processes bycarryiiig -out one stage in each of the concentrical' oven chambers and then conveying the material directly to the next one for the performance of the next stage. The advantages of this treatment may be made use of,

for example, inthe drying and dry distillation of lignite. If use is made -or thispurpose `of two concentrically arranged oven units of the revolving hearth type, the moist material is first charged onto the hearth of the outer oven' and dried. The dried material is then taken from the discharge' point of that oven and charged directly to the charging point of the inner oven. In this inner oven,- dry distillation setsin and is carried through as this oven is traversed by the mal terial. In such two stage processes, the heat given 'offby Vthe heating gases leaving the chamber of the first oven may be also utivlized fully inthe adjacent oven.

to be introduced directly into the heating chambers of the drying oven.

Several constructional forms of the invention are illustrated inl the accompanying drawings in which:

Figure lfis a partial transverse sectional view, taken on the line 1-v-1 -of Figure 1, illustrating the simplest form of the invention.

Figure 1 a is a plan view ofthe construction shown in Figure 1.

' Figu showing a second form of the invention.

re 2 1s a View similar to Figure 1,

Figure 2'lL is a section on, the line 2-2 of 'I Fi ure2.

igure 3l is a transverse sectional view showing the form ofthe invention illustrated in Figure 2 embodied in two concentrical oven chambers.` v

Figure 4 is a somewhat similar view showing in elevationthe means of transfer of material from one chamber to another.

In the arrangement shown in Fig. 1 the annular mullle a, which is enclosed in the casl ing a, is surrounded on three sides bya heating :Hue b -or direct heating. The oven cham-- b er open at the bottom is closed by the rotary hearth c. This hearth, according to this invention comprises a lower'ring e made,'for example, of ironor other metal coated-with heat insulating material provided with packing means e, supports f and depending 'flange g, to which a suitable driving means such as v 'shown in Fig. 2 can be connected, and an upper ring or hearth proper d which is rigidly connected to. the ring e by suitably spaced transverse support h. The ring 'd is located above the ring e at a distance calculated in accordance with workin@r conditions. It is thus brought more closely to the heated oven cover whereby the charge spread overl it in a thin layer is intensively heated from above. At the'same time the upper ring d is also heated from below by the radiated heat from the oven walls penetrating the free space between the rings e and al, simultaneously with heatin by the oven gases. By a specially provide current of hot gases between the rings e and d, the heating may be further increased.v If it is desired to operate mainly with heat radiation from below, it may be preferable to make the drivin ring e smaller than the hearth'ring d. I? then the lateral walls of the muiile are appropriately contracted downwardly, a substantial vincrease of the heating by radiation is ob:

tained.

An arrangement'embodying the latter feature is shown in Figs. 2, 2 and 3.

The arrangement Figs. 2 and 2 shows generally the featuresl of the oven described with reference to Figl.

`The oven arch is supported on annular posts or supports z forming between them a space for the accommodation of the travelling structure. rlfhe hearth arrangement in the example shown consists of three units rigid in themselves, i. e. the hearth ring d, the'carrier'ring e and thetravellingframe generally indicated by the character f. The latter comprises a driving rim g caused to revolve by any appropriate means'such as a worm gear g2. This rim rigidly connects the trucks lc uniformly distributed circumferentially thereof. Each bogie or truck comprises an axleqi journaled on which is a set of wheels 7c travelling on a rail track. Each bearing Z of each truck k receives a pivot pin Ztransversely to the radius of the oven. These pivot pins form the link-like or pivotal connection between the travelling structure and the hearth ring e located above the same. This ring is usually of metal coated with a heat insulating substance and is provided with the packing means e by which the oven chamber a is rendered gastight in downward direction. These packing means may consist of sand troughs or liquid seals. Connecting means for the two ring members of the hearth are provided, said means being in the form of spaced supports extending between said ring members and arranged transversely thereof and preferably radially relative to the axis of rotation of the hearths. In constructing said connecting means, the carrier ring carries, distributed over its circumference a number of bearing elements m, m which in turn support roller members n, n illustrated in Fig. 2, In the example shown, these roller members have, for exam` ple, the shape of rings made up of angle irons. These rings may be fitted loosely in the bearing elements m, m or they may also be iiXed thereto if desired. By preference, these rollers are used in pairs embracing radial ribs 0 arranged on the ring lhearth d. Loosely resting upon each of these roller pairs 1s an upper bearing block consisting of two separate members p, p forming between them a space for a rib 0. Obviously,

.this upper bearing block may be constructed in one piece provided with the space for the rib o. The revolving hearth ring d can then be freely placed on the bearing members p p', the result being that the hearth ring' is safely engaged by the travelling frame but that nevertheless the three main units may mutually adjust themselves during unequal heating.

The oven shownin Fig. 3 includes two separate revolving ring hearth oven units A and B each of a construction similar to the hearth shown in Fig. 2. The oven unit A hasa larger diameter than the oven unit B, the diameters being so dimensioned that the inner ring wall a of the outer oven coincides with the outer ring wall of the inner oven.

which includes the driving means `g. EachA ring hearth unit may be driven separately or they may be driven in unison.

In order to accomplish the transmission of material and heating gases from one oven unit to another, there is provided the construction shown in Figure 4, wherein the material is fed through the funnel y on to the outer or left-hand ring d. Above this ring is mounted the suction nozzle q which is connected, by the pipe g', to the separation chamber s. A current of air in the pipe q causes the material to be drawn from said outer ring d into the chamber s where the dust is separated and passes downwardly through the nozzle 1' on to the inner ringV d for further treatment in the inner oven chamber. The remaining material in the chamber s passes through the pipe s into a blower t from which lit is conveyed through the pipe t back into the outer oven chamber, thus providing for a complete circulation of the material from one oven chamber to another. To permit the heating gases in the inner or adjacent channels b -to flow through the heating chambers of both ovens, said channels are connected by openings al, while the outer channels b are joined together at the ports u and lw by a pipe v through which the gases in said outer channels iiow from one oven chamber to another.

What is claimed and desired to be protected by Letters Patent is 1. In a revolving ring hearth oven, an annular muiile having an open underside forming an oven chamber, a rotating ring hearth movable in said chamber, said hearth consisting of upper and lower ring members, the latter of which forms a closure for the open underside of said chamber, and the upper ring member being spaced above the lower member a distance sufficient to permit heating thereof from below, connecting means including spaced supports between said upper and lower ring members arranged transversely thereof to permit heat from the side walls of the oven chamber to enter the space between said ,ring members. said connecting means comprising pivots for joining said ring members, and a supporting and rotating structure beneath said hearth for continuously rotating the same relative to said muiiie.

2. In a revolving ring hearth oven, an annecting means comprisin nular muiiie having an open 'underside' formvthe latter of which forms a closure for the open underside of said chamber, and the upper ring member being spaced above the lower member a distance su'licient to permit heating thereoffrom below, connecting means including spaced supports Ybetween said upper and lower ring members arranged transversely thereof to permit heatl from the sidewalls ofthe oven chamber to nter the space between said ring members, sa'd conrollermembers interposed between said ring members, andv a supporting and rotating structure beneath saidhearth for continuously rotating the same relative to said 'muiilel 3. Ina revolving ring hearth oven, an annular muille-having an open undersideforming an oven chamber, a rotating ring hearth movable in said chamber, said hearth `conf sisting of upper and lower ring members, the latter of which forms a closure for the open underside of said chamber, and the upper ring member being spaced above the lower member a vdistance suiiicient to permit heating thereof from below, connecting means including spaced supports between said upper and lower ring members arranged transl versely thereof to permit heat from the side walls of the oven chamber to enter the space between said ring members, said connecting means comprlsmg roller members joining sald rlng members, a supportlng and rotating structure beneath said hearth and exteriorlyV of the oven for continuously rotating said hearth relative to said muiiie, and a plurality of pivots connecting said supporting and rotatin'g structure to said lower ring member.

4. In a revolving ring hearth oven, an annular muflle having an open underside forming an oven chamber, a rotating ring hearth 1 movable in said chamber, said hearth consisting of upper 'and lower ring members,

the latter of which forms a closure for the open underside of -said chamber, and the upper ring member being spaced above the lower member a distance suiiicient to permit heating thereof from below, connecting means including spaced supports between said upper and ower ring members arranged transversely thereof to-permit heat from the side vwalls of the oven chamber to enter the space between said ring members, said connecting means comprising roller members joining said ring members, a supporting and rotating structure including a plurality oftrucks arranged beneath said hearth lexteriorly of the oven for continuousl rotating said hearth relative to said 'muiil and a pivot carried by each truck and connected to said lower ring member.

5. In arevolving 'ring hearth oven, a pluring members, the latter of which forms av closureforthe underside of its respective chamber, and the vupper ring member being spaced above the lower rin member toper-v mit heating thereof from elow, connecting means including spaced supports between the upper and lower r1n mem rs of each hearth arranged transverse y thereof to permit heat from the side walls of the oven chamber to enter the spacebetween said ring members, said connecting means comprising pivots for joining said ringl members, and means for continuously rotating each hearth relative to its chamber.

6. In a revolving ringjhearth'oven, a plurality of annular oven chambers arranged concentrically one within another, a revolving ring hearth movable in .each chamber, each `hearth consisting of upper and lower ring members, the latter of which forms a closure for the underside of its respective chamber and the upper ring member being spaced a ove the lower rin member to permit heating thereof from low, connecting means including spaced su ports between the upper and lower rin members of each hearth arranged transverse y thereof to permit heat from the side walls of the oven chamber to enter the space betweensaid ring members, said connecting means comprising pivots for joining said ring-members, means for continuously rotating each hearth. relative to its chamber, and a casing common to said concentric oven chambers.

7.. In a revolving ring hearth oven, a plurality of annular oven chambers of different diameters arranged concentrically one within another, a revolving ring hearth in each chamber, and a casing common to and enclosing all of said chambers.

. 8. In a revolving ring hearth oven, a plurality of annular oven chambers of diiferent diameters arranged concentrically one within another, one of said chambers having a discharge point and the other a charging point f 1n communication therewith, a revolving ring hearth in each chamber, and means for transferring the material from the hearth of the first named chamber through said discharge and charging points on to the hearth in the other chamber.

9. In a revolving ring hearth oven, a plurality of annular oven chambers of different diameters arranged concentrically one within another, yone of said chambers having a discharge point and the other a charging point in communication therewith, said points providing means through which the heating gases from one oven chamber may enter di rectly into the other oven chamber, a revolving ring hearth in each chamber, and means 

